Question

Real estate ads suggest that 56 % of homes for sale have​ garages, 27 % have swimming​ pools, and 16 % have both features. ​a) What is the probability that a home for sale has a​ garage, but not a​ pool? ​b) If a home for sale has a​ garage, what's the probability that it has a​ pool, too? ​c) Are having a garage and having a pool independent​ events? Explain. ​d) Are having a garage and having a pool mutually​ exclusive? Explain.

Answer 1

Answer:

a) 0.4

b) 0.28

c) The events are not independent

d) The events are not mutually exclusive

Step-by-step explanation:

Hi!

Lets call:

Gar = {homes with garage}

Pool = {homes with pool},  

A = {homes with pool and garage}  = Gar ∩ Pool

The data we are given is:

P(Gar) = 0.56

P(Pool) = 0.27

P(A) = 0.16

a) B = {homes with garage but not pool}. This set B is the set Gar without set A: B = Gar / A  

P(B) = P(Gar) - P(A) = 0.4

b) This is a conditional probability:

P(Pool | Gar) = P(Gar ∩ Pool) / P(Gar) = 0.16/0.56 = 0.28

c) To be independent events, it must be, by definition:

P(Gar ∩ Pool) = P(Gar) * P(Pool)

0.16 ≠ 0.56*0.27 = 0.15

Then, the events Gar and Pool are not independent

d) Gar and Pool are not mutually exclusive, because there are houses with both pool and garage. We know that because P(A) is not zero.